but use names? a new study out today shows dolphin communication to be much more like ours than we ever thought. that each dolphin has its own distinct sound. essentially its own name. listen to this. one male bottlenose clicking out his signature sound, basically calling out his name. almost instantly, another dolphin responds, calling back to him by his name. >> these whistles that they produce are actually used as names. they use them to keep in contact when they're swimming through very murky waters, so they can keep their social groups integrated and operating as a unit. >> reporter: the dolphins that most commonly communicate like this? mothers to calves. you said that from a very young age, almost from birth, they start to have their signature sounds? >> absolutely. from minutes of being born, you'll see the calf vocalize. and the mother will almost mimic that. >> reporter: makes you wonder what else they're saying. matt gutman, abc news, miami. >> funny. doesn't look like a ralph. anyway. th